Portable tester for diesel fuel pumps



April 12,'1966 H. o. MAYl-:R

PORTABLE TESTER FOR DIESEL FUEL PUMPS 3 Sheets-Sheet l Filed Sept. l2, 1962 Sv A.' @n

.WW Q@ @Sk Q Swim QMQMQ Q@ Rn INVENToR, #d Mayer' y April l2, 1966 H. o. MAYER 3,245,254

PORTABLE TESTER FOR DIESEL FUEL PUMPS Filed Sept. 12, 1962 3 Sheets-Sheet 2 QW Nrw \NW .Mw/U a a www www /N N@ No mv mv luwh &../vw1+f w@ @@QQQQQ ww April 12, 1966 H. Q. MAYER 3,245,254

PORTABLE TESTER FOR DIESEL FUEL PUMPS Filed Sept. 12,' 1962 3 Sheets-Sheet 5 .92. l l 92 f4 T T /25 9/ INVENTOI; 0. Mayer United States Patent O 3,245,254 PORTABLE TESTER FOR DIESEL FUEL PUMPS Helmut 0. Mayer, 86 Swartzel Drive, Middletown, NJ. Filed sept. 12, 1962, ser. No. 223,119 12 Claims. (Cl. 73-119) This invention relates generally to portable testers for fuel pumps of diesel engines, and more particularly to the testing, measuring or calibration of their pumping action in-position and during engine operation.

Fuel pumps are used to controllably deliver fuel oil under high pressure to the spray nozzles through which the fuel is injected into the cylinders of the diesel engine. The quantity of fuel oil delivered to each cylinder is accurately measured by a corresponding section of the pump, and `at optimum is identical for each cylinder, in timed sequential relation, per pump shaft revolution. Further, such measured quantity is controlled in amount per pump revolution, or stroke, through a control rack extending from the pump. The control rack is coupled to a speed governor to leverage, as the accelerator pedal, for manual control.

'I'he arrangement and construction details of fuel pumps, per se, are varied and well known in the art, forming no part of the present invention. A widely used type has a self-contained cam and tappet combination to operate an individual plunger for each spray nozzle and cylinder of the engine. These plungers have a constant displacement, in timed Separation, through the cam. A control sleeve is concentric with and coupled to each plunger to control its angular orientation with respect t a spill port. A common control rack, linearly displaceable, establishes the settings of all the plungers, and in turn the precise quantity of fuel oil delivered by each plunger per stroke. Manual or governor control of the pump rack setting thereby determines the 'speed rand/or power output of the engine in a manner understood by those skilled in the art.

For ecient and smooth performance of the diesel engine, it is important that each of the pump sections delivers the same quantity of fuel oil per stroke to its spray nozzle, and that such delivered quantity corresponds to the control 'rack position or setting. This fuel is delivered at very high pressure over short time intervals or spurts. The spray injections by the nozzles occur at definite points in the engine cycle, and within a limited number of degrees of engine crankshaft rotation. In four-stroke-cycle engines, as in trucks, the pump camshaft is usually geared to rotate at half the engine speed.

When engine performance is impaired it is important to know the condition of the fuel injection pump. Heretofore it has been necessary to dismantle the whole pump assembly from the engine, as its pumping sectional perfonnance had to be determined on a test stand. Over fifty percent of the pumps so removed from diesel engines are found to be in good condition when tested.

The hours of unnecessary down time of the engine, and wasted skilled labor in demounting and remounting the pump, are saved by the used of the present invention. Further, the on-engine tester hereof checks the calibration of fuel delivery of each pump section over its operating range. When any plunger is thereby found to be off it is readily reset through its control sleeve to the rated position. In this way fuel pumps with merely upset plunger control settings are recalibrated in-position by the present invention. This feature is very useful in checking-out fuel pumps when rst installed on their engine; and in iinal check-out of trucks, tractors, buses, marine and stationary engines, and the like, upon completion on the production line.

In accordance with the present invention the engine itself is utilized to operateth Vfuel pump while each test icc and/or calibration is made. Only the spray nozzle for the pump section being tested is disconnected, and the engine operated on its remaining cylinders. Thus a sixcylinder engine is powered through iive of .its spray nozzles during each test run herein. The engine is not loaded beyond its contained idle-load of neutraL even for its beyond-idle-speed settings, as will be hereinafter set forth. Thus, in a vehicle, the wheels are braked and the shift placed in neutraL I have found that the diesel engines run smoothly, do not race or lug, and are fully safe in their operation with the one less cylinder.

Further, with my invention system, the pump control rack may be moved to its maximum fuel delivery per stroke setting, yet the engine power and speed, in nena tral shift, is safely controlled in such tests hereof. Towards this end, means are provided to controllably divert a portion of the fuel oil delivered at each stroke to. each of the active cylinders from the pump sections. In this manner all the pump sections deliver fuel spurts in accordance with the rack settings. The output of the selected pump section is measured, by Calibrating its fuel output over a given number of strokes, as 500. However, the activated engine cylinders receive only a controlled percentage of the pump output, in using the invention hereof.

The invention tester is portable, self-contained, and light in weight. It is readily installed in-position with the fuel pump and the engine; and the individual pump sections are rapidly tested, measured or calibrated over idle, intermediate and full rack positions. The engine itself smoothly operates the pump during its test runs herewith. The fuel pump, tested in-position, operates with its regular spray nozzles and fuel lines fand engine environment. Its operation and testing, measuring or calibration on-engine is very practical in production and inthe eld.

The above and further features, objects and advantages of the present invention system will become more apparent from the following description of exemplary embodiments and utilization thereof, illustrated in the accompanying drawings, in which:

FIG. 1 illustrates one form of the invention tester, inposition for testing, measuring or calibration of a fuel pump.

i FIG. 2 is a face view of the Calibrating vessel of the tester.

FIG. 3 is a cross-sectional view through a novel control rack setting gage.

FIG. 4 is a perspective illustration of the bleed-off control unit of the tester of FIG. l.

FIG. 5 is a diagrammatic plan View of the control unit of FIG. 4.

FIG. 6 is an enlarged transverse cross-sectional view, taken along the line 6 6 of FIG. 4.

FIG. 7 is a longitudinal cross-sectional view taken along i the une 7 7 of FIG. s.

FIG. 8 is an enlarged side view of the coupling between a fuel pump section and its lines to its nozzle and to the tester control unit, as seen along the line 8 8 in FIG. 1, in the direction of the arrows.

FIG. 9 is an illustration, in part, of yanother embodi-` ment of a tester in accordance with this invention.

FIG. l() is an enlarged face view of the bleed-off control valve of the tester of FIG. 9, as seen along the line 10-10 thereof in the direction of the arrows.

FIG. 11 is an enlarged cross-sectional view through the check-valve of the control unit of FIG. 9, taken along the line 11--11.

FIG. l2 is an enlarged side view of the coupling between a fuel pump section and its lines in the tester system of FIG. 9, as seen along the line 12-12 in the direction of the arrows.

FIG. 13 is a vertical cross-sectional view through the coupling of FIG. 12.

FIG. 14 is an enlarged perspective illustration of the valve body in the coupling of FIGS. 12 and 13.

The tester system 35 of FIG. 1 utilizes a self-contained fuel measuring means or calibrator 20. The calibrator is in a portable cabinet 21 and contains calibrating elements that measure the fuel discharge from a selected pump section. The cabinet 21 contains a bleed-olf control unit 45 with its lever 46 extending for manual setting. However, unit 45 need not be mounted in calibrator 2i). Further, the calibrator 20 per se may take several forms, for use in the tester systems of this invention.

The specific function of the calibrator 20 is to accurately measure the fuel discharge over a given number of strokes or interval of operation of any selected section of the pump being tested. Calibrator 20 is indicated schematically, as its details of construction are optional herein.

Calibrator 20 is coupled directly to the fuel pump section to be calibrated. The fuel pump 36 has six sections, with output or discharge couplings 37-1, 372, 37-6. Pump section 37-1 is under calibration in FIG. 1. It is connected to the input coupling 22 of calibrator 20 by high pressure line 38. The fuel injection pump 36 is shown in block schematic form, its construction being well known in the art. Pump 36 is driven through coupling 39 to the engine 51 which it feeds. Coupling 39 rotates the internal six-section cam that operates the plungers of the six pump sections in succession, once per cam shaft rotation or stroke Each plunger forces its measured amount of fuel oil through a discharge or delivery valve, preset at a high pressure. The delivery Valve of each section extends to the tubing union nut and washer 37 forming an independent output for the spray nozzles. The longitudinal position or setting of the control rack 40 precisely determines the quantity of fuel oil ejected by each plunger through its delivery valve and output coupling 37. Rack 40 may be manually set by linkage (not shown), and is also set by a mechanical speed governor 41 in a well known manner. The fuel pump 36 is illustrated separate from its engine 51 or equipment mounting, for clarity, it being understood that its testing and calibration herein does not entail dismantling.

During the calibration of any one of the pump sections, the remaining ones, as 37-2, 37-3, 37-6 of FIG. 1, are connected to feed their associated spray nozzles 50-2, 50-3, 50-6, as illustrated. The regular high pressure lines 52 0f the engine remain in place, and in connection with the spray nozzles 50. A three-Way coupling unit 55 is inserted between each pump output coupling 37-2, 37-3, 37-6 and the line 52 for its spray nozzle 50. A short high pressure line or link 53 couples the input of each unit 55 to its pump delivery outputvcoupling 37. A high pressure line 54, in turn, connects each coupling unit 55 to the bleed-off control unit 45.

The engine 51 is started up in the usual manner, with tester system connected-up to its as in FIG. 1, and as generally set forth hereinabove. The control lever 46 is set to zero or low bleed-off position. Fuel from the (tive) pump sections 37-2, 37-3, 37-6 is thereupon injected in turn to their associated spray nozzles 50 through coupling units 55 and lines 52. The engine 51 is kept in neutral shift. The control rack is placed in low power or idle position for low bleed-off settings of lever 46. Fuel pump section 3'7-1 feeds directly into calibrator 20, while the engine 51 operates and turns the pump cam shaft at 39.

Details of the bleed-olf control unit and its function herein are described hereinafter in connection with FIGS. 4-7. In essence, controlled proportions of the fuel directed to the operating spray nozzles are diverted through by-pass tubes 54 and unit 45. Such diverted fuel is expelled from unit 45 through spill tube 47, at low pressure. Sufiicient fuel however is injected at each stroke into each operating cylinder to effect firing and engine operation.

In the FIG. l set-up, all the fuel exiting each stroke from pump output 37-1 enters into calibrator input 22, with the line 52 to nozzle 50-1 left unconnected to the pump 36. In turn, all of the pump sections 37 are individually calibrated, in the same manner as described for 37-1. The last tested section, e.g. 37-1, has its test line 38 removed; the coupling unit 55 then on the section next to be tested (eg. 37-2) is uncoupled from the delivery coupling 37-2 and nozzle line 52; the test line 38 is then coupled directly to the new section 37-2.

The bleed-off lines 54 are not phased, so that it is unnecessary to reorient their connections to the coupling units 55, when a new pump section is connected for calibration. However, the unit 55 removed from the next section 37-2 has its link 53 coupled to the last tested section 37-1, and the corresponding nozzle line 52 connected as well. This leaves the line 52 for spray nozzle 502 open, the five remaining nozzles 50 coupled to the pump 36, and pump section 37-2 directly coupled to the calibrator 20 through test line 38. Similar reconnections are employed to individually test each of the pump sections 37-1, 37-2, 37-6.

To facilitate connection of the system 35 for calibration of a pump 36, snap-type couplings may be used for bleed-off lines 54 with units 55. FIG. 8 illustrates such an arrangement. Lines 54 are for high pressure and of flexible construction to simplify line reconnections in calibration runs for all the pump sections 37. The coupling unit 55 end of each line 54 is fitted with the coupling half 56 containing the pull back sleeve 57. The nipple half 58 of the coupling is connected with a threaded nipple 59 of unit 55. Ready connection, with positive high-pressure action and ready disconnection, of coupling 56-58, frees each unit 55 for its line changeovers. A suitable coupling for 5658 is commercially known as Snap-tite H coupling.

In a pump section test changeover, the spray nozzle line 52 is then uncoupled at nut assembly 60 from unit 55. The link line 53 is finally uncoupled at delivery end 37-6 through nut 61. Reconnection of three-way coupling unit 55 for the following test is readily accomplished with link line 53 coupled to the previously calibrated section end 37; the corresponding nozzle line 52 coupled through nut 60 to the top of unit 55; and bleed-off coupling end 56 snapped back onto nipple end 58 at unit 55.

Coupling units 55 serve to connect the fuel oil spurts pressed (at high pressure, e.g. 2300 p.s.i.) through the delivery valve outputs 37 of the pump 36 to their corresponding spray nozzles 50, as well as to the bleed-olf unit 45. A T configuration 62 through unit 55, with simple communicating bores to the three lines 52, 53, 54, effects this end. Unit 55 is built to withstand the high pressures, and its bores 62 are of the same I.D. as that of the nozzle lines 52. Link lines 53 are made short, as of the order of one inch, and have a turn. The stiff nozzle lines 52 are thus readily connected, close by their normal terminations, even if little clearing exists in any pump installation.

In the invention system 35, then, the pump sections 37 are calibrated individually, one at a time. The (five) remaining pump sections in any test run, are arranged to feed their spray nozzles 50 and cylinders, to operate the engine 51 during each test run. Each pump section 37 is calibrated at least at low, intermediate and high or full rack 40 settings. The invention system 35 arranges to divert controlled proportions of the fuel meant for the operating nozzles Si), to prevent racing of or damage t0 the engine.

The control unit 45 and its associated bleed-off lines 54 draw off sufficient fuel during each stroke to hold the engine 51 at desirable speed (and power) levels, while in neutral shift. Thus the rack 40 may be safely extended to its full setting, with maximum fuel amounts delivered through all the pump sections 37, each pump stroke. The spray nozzles 50 do not therefore know when the rack 40 is fully extended, because they then receive considerably less of each fuel spurt. This is caused by the bleedb of a preset percentage of each fuel spurt from the operation sections, into unit 45.

The rotating engine 51 therefor also rotates the pump 36 camshaft. All the pump sections thereupon operate to deliver measured amounts of fuel oil through their delivery outlets 37, at each stroke, which measures are determined by the common rack 40 setting, as aforesaid. It is such operation of the engine 51 with safety, despite even full rack 40 settings of its pump, that renders inposition calibration of the pump practical. The pump section 37-1 being calibrated (see FIG. l), delivers measured fuel at each stroke, to the test line 38. Its fuel measure is dependent directly on its plunger control sleeve angular orientation, determined by the rack 40 setting, as described hereinabove. The calibrator 20 is used to thereupon accurately calibrate this output against rack 40 settings, in a manner to be described.

The fuel delivered from the operating pump sections 37-2, 37-3, 37-6, into coupling units 55, is normally the same as that delivered by the on-test section 37-1, for any given rack 40 setting. Nevertheless, as set forth, the by-passing or bleed-olf of a preset proportion of such fuel output at each stroke from each unit 55, prevents the engine power and speed from running away or damage, since no load, or Wheels, or external braking is applied during calibration with the invention hereof.

As the rack 40 setting is increased, more fuel is delivered per stroke by all the pump sections 37. The engine 51 thereupon picks up speed, further increasing the amount of fuel it would receive per second for given settings of rack 40 and lever 46. The bleed-off control lever 46 is manually operated when the rack 40 setting is changed. In this way, one may increase the rack 40 setting during a test-run, and moderate the increase in r.p.m. of the engine 51 and pump 36. I have found such dual (40, 46) settings control to be simple, effective, and safe under all testing conditions. The tachometer 23 in calibrator 20, coupled to the engine through cable 24', is observed during the resettings of control lever 46 and rack 40.

The bleed-off control unit 45 is essentially a variable by-pa-ss valve common to all the bleed-olf lines 54. As shown in FIGS. 4 to 7, exemplary unit 45 has `a solid box-like body with a longitudinal cylindrical bore containing a common close-fitting control valve 48. A stem 49 extending from valve 48 connects with control lever 46. Cylindrical valve 48, contains five spaced transverse through-holes 42 passing through its axis of rotation. A corresponding bore 43 is contained in body 45 opposite the position of each valve hole 42. Bores 43 extend :from the valve 48 out to the input couplings 44 that connect with lines 54.

The bores 43 extend transversely across valve 48, at the axis level, as extensions 63 each communicating to a common longitudinal spill opening 64 in body 45. Opening 64 extends about body 45 as transverse channel 65 to input face 66 of the unit 45. The -spill opening 64 receives fuel oil that valve openings 42 by-pass from bores 43 into extensions 63.

Oil enters bleed-olf lines 54 at the high pressure of the outputs 37 of pump 36, and drops through valve holes 42 when opened in controlled amounts by lever 46. Such bleed-off oil flows through spill channels 64, 65. Spill tube 47 is coupled to spill channel 65 through coupling 67 at face 66. Valve body 48 is closely set in body 45, and sealed-in by end-seal 68. Control valve 45 can thus simultaneously bleed-off the same pre-set proportions of fuel discharged =by the nozzle operating 6 sections 37-2, 37-3, 37-6 of the pump, for the calibration purposes set forth hereinabove.

The exemplary calibrator 20 accurately measures the output volume of fuel oil discharged through the delivery valve of the pump section being tested (37-1 in FIG. 1), at any setting of the control rack 40. The fuel test line 38 coupled to the output 37-1 is preferably of the same size, rating, I D., and preferably also length as the engines nozzle lines 54. Line 38 is securely coupled to calibrator input coupling 22. Coupling 22 connects directly with a frnaster spray nozzle 25 .firmly bolted onto a frame 24 that contains a chamber llilled up with fuel previously sprayed in.

Nozzle 25 is replace-ably mounted, the proper master is inserted for each engine type. The master nozzle used is of the identical size and type las those 50 'of the engine 51 under test; being optional-ly factory calibrated for performance to specification. A typical American Bosch Iinjection spraynozzle, as used in six-cylinder truck diesel engines, contains an .adjustable spring set for its opening pressure for fuel injected therein by the pump; operative as at 2300 p.s.i. Each delivery valve at outputs 37 of the pump 36 contains a similar settable spring, adjusted to the same Ioperating injection fuel pressure.

The pump 'section 37-1 under calibration is thus optionally operated under conditions that closely simulate those when the engine 51 and pump 36 are in normal use. Its fuel output through nozzle 25, per stroke in-test, thus will .closely be that as though it Were in engine use, Iat all rack 40 settings. The total fuel volume discharged through master nozzle 25 over a precise number of strokes, provides the calibrated delivery of fuel by the section in-test 37-1, for any rack 40 setting. A practical stroke total of 500 yields accurately measurable fluid volumes for most test settings.

Towands this end a solenoid valve 26 connects to an output port of the chamber 24 (not shown). When solenoid valve 26 is energized it instantly establishes fuel flow from the chamber 24 out through calibration spout 27. Such energization and calibration-flow is initiated at the start of each test run, and is maintained until the pump cam shaft (at 39) has rotated for exactly 500 turn-s. The solenoid energization is thereupon instantly interrupted, and the fuel flow from spout 27 ceases, being directly shut off by the valve 26.

The calibration Afuel flow'for each test run is thus the voutput of the pump section 37-1 under test, at a recorded rack setting, for lthe 500 strokes or .pump plunger actuations. This fuel ow is collected in a graduated beaker 28 placed under spout 27 during the test-runs. Beaker 28 is yshown in enlarged view in FIG. 2. It is conical, and at its bottom has expanded 'scale readings for the smaller volumes. Beaker 28 is held in a suitable carrier.

A typical 500-stroke fuel flow for a no load 40 setting, corresponding to idling of a 175 hp. engine e.g. at 1500 r.p.'m., is 14 cc.; and for full load tor high rack setting, 52 icc. The chamber 24 is checked to be full with fuel before test runs, by observing oi-l spill-olf at' It is the solenoid valve 26 spill-olf tube (not shown). desirable to record the temperature of the fuel discharged by the master nozzle 25 into the chamber 24 and beaker 28 during the test runs. Such temperature readings may be used 'to rectify volumetric determinations of beaker 28 through a xchart, when accurate comparison is desired against Standards set for the pump 36.

Such Standards are charted at given oil temperatures, for given pumps and nozzle combinations, at designated rack settings. volume for other than the 500 strokes, either the calibrator may be reset to run for the -strokes specified per run, or a conversion ratio applied on a. per stroke basis, as will be understood by those skilled in the art. test fuel flow temperature is attained by providing a thermocouple in chamber 24.v A remote readingl indi- Irf the Standard Charts specify fuel flow The cator 29, calibrated in F., is connected to such thermocouple and mounted for observation in cabinet 21.

The calibrator 20 contains a test cycle controller schematically indicated in dotted lines at 30. Controller 30 initiates the energization of solenoid valve 26 at the start of each test-run, and automatically deenergizes the valve 26 upon the subsequent completion of a preset number of pump-section strokes, e.g. at 500 strokes. Controller 36 comprises a mechanical r.p.m. counter, with a switch that is tripped when a preset count is reached. The counter is coupled to tachometer take-off gears 31 in proper ratio to count pump strokes, i.e. its camshaft r.p.m.

The gearing 31 output is coupled to controller 30 and its counter through a shaft indicated schematically by dotted line 32. The controller 30 has an external power line connection 33, and with the counter switch controls the precise energization and deenengization of solenoid valve 26 through control leads indicated by dotted line 34. Calibrator 20 may take other forms, as stated hereinabove. Control valve 45 is optionally included in cabinet 21.

Precise reading of the positions or settings of pump control rack 40 may be directly made with a rack reader 70. Rack reader 70 is shown in cross-sectional View in FIG. 3 in position opposite rack 40, in an extended position. The frame 71 of device 70 is internally threaded at its circular open end 72 for attachment to threaded bushing 73 at the side of pump 36, through which the rack passes. The interior region 74 of frame 71 is cylindrical, and smooth. A scale rod 75 extends from a cylindrical base 76 that rides in bore 74. Scale 75 passes through an aperture in the nose 77 of frame 71, which serves as a slide support for the scale. A suitable index on the frame 71, not shown, is used to read the extended position of scale 75, in centimeters or other desirable units.

A magnet 78 is mounted in base 76, flush with its surface parallel with the end-face of the rack 40. The material of scale 75 and base 76 is non-magnetic, as aluminum or brass. The magnet 7S thus serves to press scale-base 76 flush with the rack end, and insure their physical contacting for the duration of the test runs. Rack position readings for the pump calibrations are thus simply attained, in precise terms, with rack reader 70.

It is desirable to include suitable check-valves in each snap-type coupling section 56 on the pump end of bleedoff lines 54, as Well as one at the discharge coupling 67 of the control valve 45. The oil in the lines 54 and valve 45 will thus be retained between test runs. This prevents loss of time to refill them for successive calibration runs. Further, it prevents leak-outs from lines 54 during test set-ups. Optionally suitable checkvalves may be incorporated at the valve 45 coupling ends 79 of lines 54, as well as at their ends 56.

The pump sections 37 are calibrated in any order, one at a time. These are checked-out as to fuel volume discharged during exactly say 500 strokes, regardless of the engine speed. It is preferable that the engine r.p.m. be reasonably uniform during a test run; which condition generally prevails for the preset rack settings of each run. The first calibration of a pump section 371 is generally at low speed idling for the engine (in neutral shift). The control valve 46 is turned to zero bleed-off; the rack 40 is then at a low setting which is recorded by device 70 (of FIG. 3). 'Ihe temeprature at 29 and engine r.p.m. at 23 are recorded as well.

The engine isrun at least until the spill-over from solenoid valve 26 occurs to denote a full chamber 24. The lines 54 should be full too, which condition may readily be checked by permitting fuel to flow through valve 45 and observing discharge through spill-out tube 47. Once the tests are initiated, only occasional checking of chamber 24 and lines 54 fuel-full condition is necessary, as there is negligible leakage.

A typical low-rack idling speed for the 175 hp. truck engine referred to hereinabove is 500 r.p.m., with the pump making 250 strokes per minute. The controller 30 is usually provided with a start Switch (5.8.). Pressing switch S.S. serves to simultaneously actuate solenoid valve 26 to divert fuel into calibration spout 27 and beaker 28, and to energize a clutch that initiates the counter in controller 30.

The full fuel discharge from the pump section under test 37-1 enters beaker 28 until the counter reaches itS preset total (of 500). The counter switch thereupon opens to release the solenoid 26. The volume of oil in beaker 28 represents the precise amount of fuel discharge by the tested pump section for the 500 strokes, for the run conditions as set up. Further rack settings are made successively, as desired, up to full load setting of a throttle or accelerator lever of the engine.

The fuel discharge volumes, and corresponding rack settings, r.p.m., and temperature are recorded for each run on the pump section 37-1 under calibration. As set forth hereinabove, the bleed-off control valve 45 is operated (by lever 46) to keep the engine from racing as the pump control rack (or engine throttle) are advanced. The effectiveness of the invention bleed-off principle is indicated by, for example, the diversion of 400 cc. from each operating nozzle 50 during a 500 stroke run at full load, with 12 cc. entering the nozzle to operate the engine 51 and the connected pump 36.

The aforesaid 175 hp. engine was run with only l2 cc. at full load setting, per cylinder over 500 strokes, and in neutral shift reached only about 1800 r.p.m. It had 40 cc. bleed-off at lines 54. Under normal operation, such full load high-rack setting would deliver rated power (175 hp.) at 2100 r.p.m. with 52 cc. per cylinder for 500 strokes supplied by pump 36. Such full fuel delivery to the engine is not practicable for on-engine, neutral shift, in-position pump calibration. The present invention makes this desirable result practical.

The pump is calibrated on a per stroke basis and its rack settings, per se, determine its delivery of fuel per stroke. The 500 stroke test results are thus compared to Standards for that pump. Any pump section 37 found to lbe otff may be directly readjusted in a manner well known in the art, towards its normaL The readjusted section is then recalibrated, until it is satisfactorily in adjustment. Where proper adjustment cannot be attained while it is thus on-engine, one thereupon has learned what is wrong, and the pump is then known to require repair on the bench.

A modified form 80 of the invention system is shown in FIG. 9. The multiple bleed-olf valve 45 of the system 35 (FIG. 1) is herein replaced by a single stage control valve 85. A control lever 86 is for manual setting of valve 85. A satisfactory type of valve for bleed-off control is a commercially available needle-throttling and shut-off valve. Such valve 85 should be operative at, and readily withstand, the high operating pressures involved. A common bleed-off line 81 is coupled to the valve input 82. A spill-off line 84 connects to the valve output 83.

The bleed-off control valve 85 is optionally mounted in the cabinet of the pump fuel ow calibrator 20, in the manner of valve 45 of FIG. 1. Its control lever 86 extends on the exterior opposite a scale S7. A pressure gauge 88 is connected to the input side of valve by coupling 39. Its readings are found to be useful in bleed-off manipulation.

The pump 36 in system 80 has all its sections 37-1, 37-2, 37-6 similarly connected-up. The link lines 53 are coupled to the pump sectional delivery valve outputs 37, and in turn connect with individual pressure line valve units 90. Each valve unit 90 has a two-position lever 91 that is set in accordance to which pump section 37 is to be tested. This feature eliminates the need to reconnect the bleed-off lines 54 and nozzle lines 52 in changing over for testing successive pump sections. The set-up of these lines is for all (six) sections 37, and suces 9 for all the test runs on the pump with invention system 80.

Test line 38 is coupled to the line valve 90 at the pump section selected for testing; at 37-1 in FIG. 9. The lever 91 of this valve 90 is turned towards the test line 38 connection at its horizonal position shown in FIG. 12. Such valve setting 91 disconnects the bleed-off line 54 and the nozzle line 52 from the link line 53 of that section 37-1, and directly connects the test line 38 with that link line. The full fuel output of the section under test 37-1 will thereupon ow into test line 38. Line 3S is also connected to the input 22 of a fuel flow calibrator 20, as already described in connection with system 35 of FIG. 1.

The spray nozzle lines 52 each couple to the corresponding sections line Valve 90. Also, a bleed-off line 54 extends from each line valve 90 directly to bleed-off block 95. It is understood that all (six) nozzle lines 52 are in connection with valves 90, with only one shown in FIG. 9, for clarity of presentation; and that lines 52 terminate at their respective nozzles 50 as described in connection with FIG. 1.

The bleed-lines 54 terminate in common block 95 through individual couplings 92. Bleed-off block 95 contains a central cavity 96 communicating to connecting bleed-off lines 54. Each bleed-olf coupler 93 of block 95 directly connects with chamber 96 through a bore 94, and with a line coupling 92. There are eight couplers 93 in block 95, two of which are capped 97 when a six section pump is under test. An exit bore 98 to chamber 96 communicates to common exit line 81 through coupling 99.

The operation and exemplary construction of line valves 90 are illustrated in FIGS. 12-14. Each valve 90 is in the form of a block 100 containing a central valve disc 101 closely seated therein. Disc 101 is rotatable between its two 'operating positions through lever 91 on extending central rod 111. Block 100 contains bores 102, 103, 104, 105 from its central chamber to its coupling faces. Coupling 112 extends from bore 102 and connects with test line 38; 113 from bore 103, with bleedoff line 54'; 114 from bore 104, with link line 53; and 115 from bore 105, with nozzle line 52. A

l When lever 91 is in the to-test-line position shown in solid lines in FIG. l2, the valve disc 101 is oriented as seen in FIG. 13. Its central through-bore a-c directly couples lines 38 and 53'; while its T bores b-d-e are sealed-in. Also block bores 103 and 105 are blockedoif. This position thus conducts the fuel output of the pump section 37-1 under test to test line 38 and on to calibrator 20 while arresting any output therefrom to its nozzle and bleed-off lines 52, 54.

When lever 91 is in its to operation position 91a shown in dotted lines in FIG. 12, the valve disc 101 is oriented with its T bores b-d-e communicating with block-bores 105, 104, 103 respectively. Through-bore i a-c is thereupon blocked-off. This position is used for all the engine operating sections, and feeds the pump discharges into respective bores 104 and d, directly to their associated nozzle lines 52 and bleed-off line 54.

The calibration of the fuel ow of the pump sections 37 with system 80 is performed similarly to that described hereinabove for system 35. The lever 91 for the test line 38 section 37-1 is turned horizontally, and the others to the operating or bleed-olf position 91a. The pump section under test discharges directly into calibrator 20, while the remaining sections 37-2, 37-3, 37-6 operate the engine 51. The bleed-oft lines 54', cavity 96 of block 95, and line 81, are rst lled with fuel oil, with the engine in low rack at idling. Control valve 85 is at or near closed, then. This setting is usually the setting for the first test run and its rack setting.

For increased rack settings, the lever 86 is used to open valve 85 slowly and progressively as the rack is moved higher, and thus keep the engine under control and safe, as already set forth. The degree of bleed-olf of fuel oil from the operating sections, through lines 54', block 95, line 81 and valve 85 is thereby -under control of the setting of lever 86. To calibrate successive pump sections 37, one simply `resets the levers 91 of line valves 90, and reconnects test line 38 to that valve 90 at the next section selected for test, the remaining levers 91 being set into operation position 91a, as will now be understood by those skilled in the art.

The bleed-off lines 54 are relatively short compared to those 54 of system 35 (FIG. l); e.g. of the order of one foot. They may thus be continually attached to bleed-olf block 95 through couplings 92, 93. Lines 54 are fabricated to operate under the high pressures of the fuel system hereof, e.g. 2300 p.s.i. Their coupling with line valve connection 113 (FIG. l2) preferably contains ya check valve to contain fuel oil in the lines 54'. Further, such couplings 110, 113 may conveniently be of the snap-type as for lines 54 at 56, 57, 58 (see FIG. 8). l

The block input couplings 93 each contain an internal check valve constructed to prevent fuel oil, bled through lines 54 and passing into chamber 96 from being divertedback into the same or any other line 54. All bled-off fuel is therefore uniform among the lines 54', and passes on through common line 81 to valve 85. This results in proportional bleed-off control 86 for all the operating nozzles 50, and insures smooth neutral shift performance of the engine 51 over all the rack 40 settings of the test runs, despite operation on one less cylinder, as already set forth.

An exemplary check valve for input couplings 93 is shown in enlarged cross-sectional view in FIG. 1l. Check valves 120 each comprise a nipple 121 threaded into block 95 at an input bore 94. A spherical ball 122 is pressed against the aperture 123 by a spring 124 contained within nipple 121. The pressure of spring 124 on the ball 122 effects a seal at its close fitting juncture with the aperture 123. However, the pressure of fuel entering bleed-off lines 54 from line valves 90 overcomes the pressure preset in springs 124 to open the ball seal. However, when no fuel is being discharged by a pump section 37 in its operation cycle, the ball seal 122, 123 prevents fuel oil in chamber 96 from backing up into the corresponding line 54.

The testers of the present invention are very effective in directly determining the efficiency or proper setting and balance of fuel pumps of diesel engines, and their associated governors. This is readily performed, economically of labor and engine (and vehicle) down-time. The fuel pump is not removed for the testing and concomitant adjustments. VThe most significant tests are under full load condition of the pumps operation, with its control lever or rack correspondingly extended.

For example, a Atruck with an engine rated at 2350 r.p.m. full speed, has its governor start cutting-off fuel settings at that peak speed. Such engine is preferably tested at 2000 or 2100 r.p.m. by the systems hereof in order to avoid any cut-olf action during test runs. Pump rack settings at full load fuel delivery thus holds such setting during the calibration or measuring runs of the selected pump sections.

The high-speed full-load (full-rack) test is attained with the testers of the invention as follows: The calibration line 38 of the tester is set up to deliver the fuel from the pump section under test 37-1, to the measuring unit 20; and the remaining pump sections, to controllably deliver fuel to their associated engine nozzles. The throttle or pump rack is then gradually moved to higher and higher settings, until the engine speed reaches about 2000 r.p.m. The pump fuel delivery, per se, is then further increased through throttle and/ or rack, while the bleed-off control 46 or 86 of the tests of FIG. 1 or 9 (or pulsator setting 154-155), is operated to correspondingly reduce fuel delivery from the pump 36 to the nozzles 50. In this manner the pump rack setting, and/ or throttle, is thereby moved towards and finally into full-load position. The engine is thereby placed in safe operation, near its fullspeed as at 2000 r.p.m. even though its gear shift is in neutral, with no need of real loading-down or braking. The bleed-off or pulsator control, in the system herein, inhibits in a controllable manner the fuel ow from the pump sections to the engine nozzles. The selected pump section 37-1 feeds the test fuel amount to the measuring unit 20, while the engine is controllably held at the high speed (2000 r.p.m.) for a desired number of strokes, as 500. The test fuel delivery, in beaker 28, is compared to the Standard for the particular pump, as from a Service Chart. The other pump sections are similarly tested, in turn. In practice, holding the engine speed between 1900 and 2100 r.p.m. during any 2000 r.p.m. test run, provides satisfactory and repetitive readings.

A further useful test series on a fuel pump, in-position on its diesel engine, is at an intermediate-speed, as at 1500 r.p.m. Such test is particularly indicated when the associated governor is of the droop-screw type, and corresponds to its actuation in a truck on up-hill full-load operation at lower-than-full speed, as at 1500 r.p.m. The test procedure for such run is similar to that herein described for the 2000 r.p.m. series, attaining the 1500 r.p.m. with full-rack setting of the pump control, properly bled-olf or pulsated therefor. In practice, maintaining a 1400-1600 r.p.m. range during the test runs, gives satisfactory readings and results.

Ready interpretation of these tests, as to the adjustment and balance of the fuel pump sections and/or its governor permit such direct adjustments as are feasible on-engine. Removal of the pump and/or governor, through the invention in-position testing, is minimized. Further, the testing of distributor-type pumps is effective and simple with the inventiton testers. The testing of one pump section thereof provides results as to the adjustment, delivery, and operation for all of the pump.

Although the present invention has been illustrated and described in connection with several embodiments thereof, it is to be understood that variations and modifications of the systems and their component parts, as well as their applications, may be made that fall within the broader spirit and scope of this invention, as set forth in the following claims.

I claim:

1. In a system for in-position testing the discharge of fuel from the individual output sections of the injection pump coupled by lines to the plural spray nozzles of a diesel engine and driven thereby, and wherein the setting of a unitary control element adjusts the volume of fuel discharged per stroke in succession by each pump section for its associated spray nozzle: a fuel volume measuring unit; means for conducting the fuel output of a selected for testing pump section to said measuring unit; and control means for reducing fuel output to the nozzles after discharge from the remaining associated sections of the pump, and thereby correspondingly substantially uniformly control the reduced amount of fuel entering their respective spray nozzles of the engine for its operation of the pump during its in-position testing as compared with the basic fuel output from said sections normally determined by the indicated control element setting, whereby the engine is operatively fueled by said remaining pump sections while the selected pump section is being tested.

2. In a system for testing the delivery of fuel from the individual output sections of the injection pump coupled to the plural spray nozzles of a diesel engine and driven thereby, and wherein each pump section is coupled to a unitary control element the setting of which adjusts the volume of fuel delivered per stroke in succession by each pump section for its associated spray nozzle in successive spurts: a fuel volume measuring unit; means for conducting the fuel output of a selected for testing pump section to said measuring unit; and control means for inhibiting fuel output to the nozzles after discharge from each of the remaining associated sections of the pump, and thereby correspondingly controllably reduce the amount of fuel entering their respective spray nozzles of the engine for its operation of the pump during its testing as compared with the basic fuel output from said sections normally determined by the indicated control element setting, whereby the engine is operatively fueled by said remaining pump sections while the selected pump section is being tested.

3. In a system for in-position testing the delivery of fuel from individual output sections of the injection pump coupled by lines to the plural spray nozzles of a diesel engine and driven thereby, and wherein each pump section is controllable by the setting of a unitary control element which adjusts the volume of fuel discharged per stroke in succession by each pump section at high pressure for its associated spray nozzle: a unit for measuring the fuel output of a pump section selected for testing; means for conducting the fuel output of the selected pump section to said measuring unit; and unitary control means for reducing fuel output to the nozzles after discharge from each of the remaining associated sections of the pump, and thereby correspondingly substantially uniformly reduce the amount of fuel entering their respective spray nozzles of the engine for its operation of the pump during its in-position testing as compared with the basic fuel output from said sections normally determined by the indicated control element setting, whereby effective operation of the engine and pump together is provided during test runs on the selected pump section with the engine being fueled through said remaining pump sections.

4. In a system for in-position testing the discharge of fuel from the individual output sections of the injection pump coupled by lines to the plural spray nozzles of a diesel engine and driven thereby, and wherein each pump section is controllable by the setting of a unitary control rack which adjusts the volume of fuel discharged per stroke in succession by each pump section at high pressure for its associated spray nozzle in successive spurts: a fuel volume measuring unit; means for conducting the full fuel output of a selected for testing pump section to said measuring unit; individual means for hydraulically coupling to the fuel output of the remaining sections of the pump and to their respective spray nozzle lines; and unitary control means for diverting fuel output from each of said remaining pump sections after their fuel diS- charge, and thereby correspondingly reduce the amount of fuel entering their associated spray nozzles of the engine to an amount sufficient for its operation of the pump during its in-position testing as compared with the basic fuel output from said sections for an indicated rack setting, said control means including individual auxiliary lines extending from the hydraulic coupling means and thereby establish an hydraulic circuit from the fuel output of each of said remaining pump sections to the inputs of their associated spray nozzles as Well as to said control means, whereby elfective and safe operation of the engine and pump together is provided during test runs on the selected pump section over the range of settings of the pump control rack with the engine being fueled through said remaining pump sections.

5. In a system for in-position testing the delivery of fuel from individual output sections of the injection pump coupled by lines to the nozzles of a diesel engine wherein each pump section is controllable by setting of a unitary control element which adjusts the volume of fuel delivered per stroke in succession by each pump section at high pressure for its associated spray nozzle in successive spurts, and wherein the pump sections are driven by the engine: a fuel volume measuring unit; means for conducting the fuel output of a selected for testing pump section to said measuring unit; individual means for hydraulically coupling to the fuel output of the remaining sections of the pumpand to their respective spray nozzle lines, each of said coupling means having a connection hydraulically communicating with the fuel output of its associated sectional pump; and unitary control means for bleeding-off predetermined portions of the fuel output as discharged from each of said remaining pump sections, and thereby correspondingly substantially uniformly reduce the amount of fuel entering their associated spray nozzles of the engine connected therewith as compared with the basic fuel output from said sections normally determined by an indicated control element setting, said control means including an individual auxiliary line for coupling with the individual hydraulic connections of said coupling means and thereby establish an hydraulic circuit from the fuel output of each of said remaining pump sections to the inputs of their associated spray nozzles as well as to said control means, whereby effective and safe operation of the engine and pump together is provided during test runs 0n the selected pump section at safe -engine power and speed levels over the range of settings of the pump control element with the engine being fueled through said remaining pump sections.

6. A system as claimed in claim 5, in which said control means includes a body with ports for connection with each of said auxiliary lines and valve means Within said body communicating with said ports for controlling the degree of said fuel bleeding-off in unison from said remaining pump sections.

7. A system as claimed in claim 4, in which said control means includes a body with ports for connection with each of said auxiliary lines and valve means hydraulically coupled to said body and its ports for controlling the rate of said fuel diversion in unison from said remaining pump sections.

8. A system as claimed in claim 4, in which each of said coupling means includes a Valve for cutting-off the hydraulic coupling of its `sectional pump output with said associated spray nozzle line and auxiliary line, and a further connection in said coupling means for said conducting means wherein the associated pump section fuel output is arranged to pass therein upon said valve cut-off position and thereby directly establish the associated pump section as the one for testing.

9. A system as claimed in claim 5, in which each of said coupling means includes a valve for cutting-off the hydraulic coupling of its sectional pump output with said associated spray nozzle line and auxiliary line, and a further connection in said coupling means for said conducting means wherein the associated pump section fuel output is arranged to pass therein upon said valve cut-off position and thereby directly establish the associated pump section as the one for testing.

10. A system as claimed in claim 1, in which said fuel measuring unit contains a test spray nozzle and said fuel output conducting means connects with said test spray nozzle whereby the selected pump section is rendered substantially normally operative during its being tested.

11. A system as claimed in claim 3, in which said fuel measuring unit contains a test 'spray nozzle and said fuel output conducting means connects with said test spray nozzle whereby the selected pump section is rendered substantially normally operative during its being tested.

12. A system as claimed in claim 5, in which said fuel measuring unit contains a test spray nozzle and said fuel output conducting means connects with said test spray nozzle whereby the selected pump section is rendered substantially normally operative during its being tested.

References Cited by the Examiner UNITED STATES PATENTS 2,062,173 11/1936 Haskins 73-118 X 2,720,782 10/ 1955 Stein 73e118 FOREIGN PATENTS 712,876 10/ 1941 Germany. 574,35 3 1/ 1946 Great Britain.

RICHARD C. QUEISSER, Primary Examiner.

DAVID SCHONBERG, Examiner. 

1. IN A SYSTEM FOR IN-POSITION TESTING THE DISCHARGE OF FUEL FROM THE INDIVIDUAL OUTPUT SECTIONS OF THE INJECTION PUMP COUPLED BY LINES TO THE PLURAL SPRAY NOZZLES OF A DIESEL ENGINE AND DRIVEN THEREBY, AND WHEREIN THE SETTING OF A UNITARY CONTROL ELEMENT ADJUSTS THE VOLUME OF FUEL DISCHARGED PER STROKE IN SUCCESSION BY EACH PUMP SECTION FOR ITS ASSOCIATED SPRAY NOZZLE; A FUEL VOLUME MEASURING UNIT; MEANS FOR CONDUCTING THE FUEL OUTPUT OF A SELECTED FOR TESTING PUMP SECTION TO SAID MEASURING UNIT; AND CONTROL MEANS FOR REDUCING FUEL OUTPUT TO THE NOZZLES AFTER DISCHARGE FROM THE REMAINING ASSOCIATED SECTIONS OF THE PUMP, AND THEREBY CORRESPONDINGLY SUBSTANTIALLY UNIFORMLY CONTROL THE REDUCED AMOUNT OF FUEL ENTERING THEIR RESPECTIVE SPRAY NOZZLES OF THE ENGINE FOR ITS OPERATION OF THE PUMP DURING ITS IN-POSITION TESTING AS COMPARED WITH THE BASIC FUEL OUTPUT FROM SAID SECTIONS NORMALLY DETERMINED BY THE INDICATED CONTROL ELEMENT SETTING, WHEREBY THE ENGINE IS OPERATIVELY FUELED BY SAID REMAINING PUMP SECTIONS WHILE THE SELECTED PUMP SECTION IS BEING TESTED. 